As evidenced by the prior U.S. Pat. No. to Berch 2,135,479, Vogel U.S. Pat. No. 3,590,557 and Young et al U.S. Pat. No. 3,695,900, among others, it has been proposed in the prior art to close and seal the open end of a container by heat sealing across the open end a suitable end closure member. The use of a relatively thin foil or laminate "patch top" end closure members instead of the conventional relatively heavy gage metal ends having rolled seam connections has also been proposed (for example, in the "snack foods" packaging art). Furthermore, the use of reusable circumferentially-flanged overcaps is well known in the art (for example, in connection with tennis ball cans, and containers for snack foods, toys and the like).